Thank you very much. Here is the panic message, just in case you might need that:
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x29e4521]
goroutine 8054 [running]:
github.com/pydio/cells/vendor/github.com/etcd-io/bbolt.(*Bucket).Cursor(…)
/opt/teamcity/agent/work/fb9e7e7133d45375/go/src/github.com/pydio/cells/vendor/github.com/etcd-io/bbolt/bucket.go:84
github.com/pydio/cells/broker/chat.(*boltdbimpl).RoomByUuid.func1(0xc001267a40, 0x0, 0xc001267a40)
/opt/teamcity/agent/work/fb9e7e7133d45375/go/src/github.com/pydio/cells/broker/chat/bolt.go:224 +0x91
github.com/pydio/cells/vendor/github.com/etcd-io/bbolt.(*DB).View(0xc001056600, 0xc009d06eb8, 0x0, 0x0)
/opt/teamcity/agent/work/fb9e7e7133d45375/go/src/github.com/pydio/cells/vendor/github.com/etcd-io/bbolt/db.go:719 +0xa8
github.com/pydio/cells/broker/chat.(*boltdbimpl).RoomByUuid(0xc000fb3820, 0x3, 0xc00998c750, 0x24, 0xc008a430b0, 0x0, 0x0)
/opt/teamcity/agent/work/fb9e7e7133d45375/go/src/github.com/pydio/cells/broker/chat/bolt.go:222 +0xf5
github.com/pydio/cells/broker/chat/grpc.(*ChatHandler).PostMessage.func1(0xc009019a60, 0x7fde1801f1e0, 0xc000fb3820)
/opt/teamcity/agent/work/fb9e7e7133d45375/go/src/github.com/pydio/cells/broker/chat/grpc/handler.go:129 +0x263
created by github.com/pydio/cells/broker/chat/grpc.(*ChatHandler).PostMessage
/opt/teamcity/agent/work/fb9e7e7133d45375/go/src/github.com/pydio/cells/broker/chat/grpc/handler.go:120 +0x371